Folding sliding doors



July 18, 1967 R. COLOMBO 3,33127 FOLDING SLIDING DOORS Filed July 26, 1965 2 Sheets-Sheet l July 18, 1967 R. COLOMBO FOLDING SLIDING DOORS 2 Sheets-Sheet 2 Filed July 26, 1965 United States Patent tice Y 3,331,427 Patented July 18, 1957 3,331,427 FQLDING SLIDING DOORS Roberto Colombo, Turin, Italy, assigner to Lavorazione Materie Plastiche L.M.P. S.p.A., Turin, Italy Filed July 26, 1965, Ser. No. 474,861

Claims priority, application Italy, Aug. 3, 1964,

4,566/64 6 Claims. (Cl. 16d- 199) ABSTRACT F THE DISCLOSURE A sliding door having `a plurality of identical hollow plastic slats which are interconnected for accordion type folding. An overhead horizontal track wherein are slidably aligned extruded plastic runners which are centrally secured to each panel to guide and support the panel during folding and unfolding. A leading slat having handles and a wheel carrying runner secured thereto and having two sets of wheels rollable in the track and a compensating slat interconnecting the leading slat and the series of identical slats.

This invention relates to folding-sliding doors comprising an overhead horizontal track, a series of runners supported by the track, and a series of vertically extending slats depending from their respective runners in a mutually hinged zig-zag arrangement, wherein each of said slats is capable of pivoting about its longitudinal central axis whereby the series of slats can be folded up and unfolded like an accordion.

Moreover, a door of the just defined character usually comprises a leading slat or post constantly maintained by its runner in a co-planar relation to the track, and a compensating slat linking said series of slats to the leading slat, said compensating slat having a width substantially equal to the half-width of a slat in the series,

Folding up and unfolding of the door is usually accomplished by pushing and pulling, respectively, the leading slat, a pair of hand grips being provided to that end on the opposed faces of the latter at a suitable height from the oor. It is also known that an unexpected high degree of skill is required for successfully manoeuvring the door without causing jamming of the runners in the track. Jamming easily occurs in light-weight doors, because of the ease with which the slats are deflected from their straight-down depending -condition by inexpert hands; heavy-weight slats reduce the probability of jamming, but require both very sturdy tracks and runners and considerable muscular etforts for operating the door. The probability of jamming can also be reduced by suspending the slats from their respective runners by means of universal joints; however, this and other known expedients (generally borrowed from the art of overhead monorail conveyors) are relatively cost-ly and require a substantial space, the latter being another problem characterizing the folding-sliding doors. Actually, since folding up of a door involves a progressive closure to zero-value of the dihedral angle between each pair of slats in the series, it is obvious that the space available lengthwise of the track for each of the runners cannot exceed the thickness of its respective slat (except for the lead-ing slat which is constantly co-planar with the track).

Accordingly, it is an object of this invention to provide, in a light-weight folding-sliding door of the hereinbeforedefined character, non-jamming runners requiring but a little space lengthwise of the track. Another object of this invention is to provide a light-weight folding-sliding door comprising said non-jamming runners structurally combined with slats of extruded plastics, such as rigid polyvinyl chloride, said runners consisting each of but a single faces, providing piece of moulded plastics iitted to one end of its associated slat without the use of screws, bolts or other fasteners. Still further objects and advantages of this invention will be evident from the following description and the accompanying drawings.

According to the invention, a folding-sliding door is provided comprising an overhead horizontal track, a series of runners supported by the track, and a series of vertically extending slats depending from their respective runners in a mutually hinged zig-zag arrangement, each of said slats being capable of pivoting about its longitudinal central axis whereby the series of slats can be folded up and unfolded like an accordion, characterized in that: (a) each of the slats in the series essentially consists of a dat hollow prole of extruded plastics including a pair of partitions interconnecting the opposite face walls of the profile at locations enclosing therebetween the longitudinal Central axis of the latter; (b) each of the runners comprises a stirrup section encased in the upper end of the slat between said partitions, a cylindrical neck section protruding outwardly from the stirrup section in alignment with said longitudinal central axis, and an enlarged head section on said neck section comprising a spherical surface turned towards the stirrup section, said stirrup section comprising resiliently expandable branches having each an outwardly projecting tooth thereon snap-fitted into an aperture in its respective partition whereby the runner is anchored to the prolile; and (c) the track comprises an inverted channel member having inturned opposed flanges jointly supporting therebetween the spherical surface on the head sections of the runners for sliding movement lengthwise of the track.

In the accompanying drawings:

FIGURE l is a part plan-view of an embodiment of the invention;

FIGURE 2 is a perspective view of a runner;

FIGURE 3 is a cross-sectional view on a Vertica-l plane showing the suspension of one of the runner-equipped slats;

FIGURE 4 is a cross-sectional view on line 4 4 of FIGURE 3;

FIGURE 5 is a view similar to that of FIG. 4, referring to the upper end of the leading slat;

FIGURE 6 is a cross-sectional view on line 6 6 of FIGURE 5;

FIGURE 7 is a perspective view of the runner (deprived of its wheels) of the leading slat.

In the embodiment shown, the supporting (fixed) structure of the door comprises a pair of posts 10', 11 bridged by a horizontal overhead track 30, consisting each of an extruded profile of rigid polyvinyl chloride or other suitable synthetic resin composition. Each of the posts includes a dovetailed groove 12 and is xed to its supporting wall by means of screws 13 screwed through the bottom of said grooves; the heads of the series of screws in each of the posts are concealed by means of a strip 14 of flexible plastics of an arcuate cross-sectional shape snap-inserted into its respective groove.

Similarly, the track 3i) (FIGURES 3 and 6) includes a dovetailed groove 36a and is fixed to its suporting ceiling by means of screws 13a screwed through the bottom of the groove; the heads of the series of screws 13a are concealed by means of a strip 14a, identical to the strips 14, snap-inserted into the groove 30a.

The movable structure of the door comprises a plurality of slats, indicated by 15, 16, 17, 18, 19, and 20, consisting each of a at hollow extruded profile of rigid polyvinyl chloride or other suitable plastics. Said plurality of slats comprises a leading slat 20, extruded integrally with a pair of wings 20a, 20a, on its opposite planar handgrips for maneuvering the door. The

leading edge of the leading slat is rounded and engages in a channel 11a in the post 11 in the closed condition of the door. The anks of the channel 11a resiliently grip the slat in said condition. n

The body of the door is formed by a series of slats of which the slats 16, 17 and 18 are the representatives in the drawing, said slats being identical to each other and being connected to the post and to the leading slat 20 through the interposition of compensating slats 15, 19, respectively. All the slats are hinged to each `other by means of strips 22 of ilexible plastics, advantageously polypropylene, severed from a common stock, and a similar strip 22A is used as hinge between the compensating slat and its associated post 1G. Each of the two opposite longitudinal edges of each of said strips consists of a circular Vbead 22a, 22b, respectively, said beads being inserted as tenons in their respective mortises formed in the corresponding slats. Under this aspect, reference is made herein to the British patent specification 927,590 showing similar hinges and also to my co-pending application Ser. No. 474,905 led in even date herewith, according to which the tenons are loosely rotatable in their mortises so that each of the hinges functions in part by the rotation of the tenons and in part by ilexure of the web of the strip interconnecting the tenons. One of the tenons of the strip 22A is inserted into its corresponding mortise 10a formed in the post 10 lengthwise of the dovetailed groove 12.

Each of the slats 16, 17, 18 forming the body of the door has its opposite face walls interconnected by a plurality of partitions integrally extruded with the slat, comprising a pair of partitions 16a, 1617 equally spaced at opposite sides of the longitudinal central axis X of the slat. TheV general purpose of the partitions is to reinforce and stiien the slats; further reinforcing partitions are denoted by 15a and 19a in the case of the compensating slats 15 and 19, respectively. However, the specic partitions 16a, 16h mentioned above have a particular function in this door, as will be evident hereinafter. It is to be noted, moreover, that also the leading slat (FIG. 5) comprises a similarly specific pair of partitions 20A, 20B, equally spaced at the opposite sides of the longitudinal central axis Y of the slat. The space between said specific partitions (both in the slats 16 18 and in the leading slat 20) is rectangular in cross-sectional shape.

For the sake of simplicity of the description, slat 16 will now be taken as representative of each of the slats 16 18 forming the body of the door. Said slat is suspended from the track by means of a runner R which is separately shown in FIG. 2 and the arrangement of which is shown in FIGS. l, 3 and 4.

The runner is integrally moulded from a high-impact, wear-resisting synthetic resin composition, such as nylon,

` for example, and comprises a-stirrup section 34, a cylindrical neck and ahemispherical head 36. More specifically, the stirrup section comprises a pair of resiliently expandable branches 34a, 34a, and its outer proifle matches the rectangular space between the partitions 16a, 16b in the slat 16, except for a tooth or hook 34b projecting laterally outwardly from each of the branches. Thus, by resiliently exing the branches towards each other, the stirrup section can be slid into said space between the partitions to a depth defined by a pair `of apertures 32, 32,V formed in the partitions, into which the teeth 34b snappingly engage due to resilient expansion of the branches. In this manner the'stirrup section is firmly locked in the upper end of the slat 16. The neck 35 protrudes upwardly from the stirrup section in alignment with the axis X of the slat; the hemispherical surface on the head 36 ofthe runner is turned towards the stirrup section, i.e. downwardly, and its diameter does not exceed the thickness lof the slat 16 (FIG. 3).

It will be also seen in FIG. 3 that the effective crosssectional shape of the track 30 is that of an inverted U or inverted channel comprising a pair Vof inturned op- A posed iianges 39h, 3tb; the latter have planar smooth Y upper surfaces and enclose therebetween a slot of a width slightly greater than the diameter of the neck 3S of the runner R (but substantially smaller than the diameter of the head 36). Thus, the heads of all the runners associated with the body of the door can be slid into the track 30 thereby to pendularily support the slats 16 1S from the track. As a pull is exerted on the leading` slat, the heads 36 of the runners slide lengthwise of the track on the flanges 30b Iand rotate at the same time 4through an angle corresponding to the rotational angle of the slats; in this manner the door unfolds (or folds up) smoothly and wear of the heads is practically negligible, particularly when (as is obvious to those skilled in the art) the edges of the flanges 30b have been preliminarily beveled. On the other hand, replacement of lthe runners R is relatively quick `and easy; actually, it is sucient to press inwardly the teeth 3412 (even |by ngertips) and withdraw the runner from the slat. t

The runner R of the leading slat (FIGS. 5, 6 and 7) is what is commonly known as trolley, comprising two pairs of wheels 42 rolling on the upper planar surfaces of the anges 3611 of the track 30. Thus,` said flanges perform two different functions, viz. the function of slidably supporting the heads 36 on runners R and the function of rollably supporting the wheels 42 of the runner R'. The latter moreover comprises a stirrup section 34A which is structurally identical to the stirrup section 34 of the runners R and is snap-encased between the partitions 28A, 20B of the leading slat, with its teeth 34b engaged in apertures 32a in said partitions and with its outline matching the cross-sectional shape of the space between the partitions. The stirrup section 34a is moulded integrally with an elongated wheel-carrying body 40, consisting of a horizontal rectangular-prismatic bar co-planar with the leading slat 20, and depends from a longitudinally intermediate portion of said body. The opposite ends of the body project beyond their respective partitions 20A, 20B and have each depending therefrom a block 40a integrally moulded with the body (of `a high-impact wear-resisting plastics, such as nylon). The blocks 40a transversely lill the space 'between the opposite face walls (FIG. 6) of Y'the leading slat 20 in the upper end of the latter and provide in this manner a pair of coupling dogs eifective between the body 40 and slat around the axis Y to maintain these components in their co-planar relationship. A pair of transverse holes 41 isV formed in the body 4f! at locations adjacent the opposite ends of the latter, each of said holes having inserted therethrough a metal spindle rotatably supporting its respective pair of wheels 42.

On assembly ofthe door, the body 40 is inserted lengthwise into the track 3) and is guided parallel to the latter by the pairs of Wheels 42, so that the leading sla-t is constantly co-planar with the track. t

What I claim is:

1. Folding-sliding door comprising an overhead horizontal track, a series of runners Ysupported Iby the track, and a series of vertically extending slats depending from their respective runners in a mutually hinged zig-zag larrangement, each of said slats being capable of pivoting about its longitudinal central axis whereby the series of slats can be folded up and unfolded like an accordion,

plastics including a pair of partit-ions spaced from the Y ends of the profile interconnecting the opposite face walls` ofthe prole at locations enclosing therebetween the longitudinal central axis of the latter; (b) each of the runners comprises a stirrup section encased in the upper end of the slat between said partitions, a cylindrical neck section p Y Y protruding outwardly from the stirrup section in alignment with said longitudinal central axis, and an enlarged head section -on said neck section comprising `a spherical surface turned towards the stirrup section, said stirrup section comprising resiliently expandable branches having each an outwardly projecting tooth thereon disposed in a plane parallel to the face walls and adapted -to be snapiitted into an aperture in its respective partition whereby the runner is anchored to the prole; and (c) the track comprises an inverted channel member having inturned opposed anges jointly supporting therebetween the spherical surface on the head sections of the runners for sliding movement lengthwise of the track.

2. Folding-sliding door as claimed in claim 1, characterized in that the stirrup, neckand head sections of each of said runners are integrally moulded of a highimpact, wear-resisting synthetic resin compositori.

3. Folding-sliding door as claimed in claim 1, characterized in that the prole of the stirrup section of each runner matches the cross-sectional profile Of the space between said partitions.

4. Folding-sliding door as claimed in claim 1, moreover comprising a leading slat equipped with a fourwheeled trolley keeping the leading slat co-planar with the track, characterized in that: (a) the leading slat essentially consists of a at hollow profile of extruded plastics including a pair of partitions interconnecting the opposite face walls of the prole at locations enclosing therebetween the longitudinal central axis of the latter; (b) said trolley comprises a stirrup section encased in the upper end of the leading slat 'between said partitions, an elongated wheel-carrying body integral with said stirrup section, and at least one coupling dog depending from said body into the upper end of the profile at a location beyond one of said partitions; said stirrup section comprising resiliently expandable branches having each an Outwardly projecting tooth thereon snap-fitted into an aperture in its respective partition whereby the .trolley is anchored to the prole; said wheel-carrying body being equipped with two pairs of wheels rollable in the track on the inturned opposed anges of the latter.

5. Folding-sliding door as claimed in claim 4, characterized in that the stirrup-section yand the body of the trolley are integrally moulded of a high-impact, wearresisting synthetic resin composition.

6. Folding-sliding door as claimed in claim 4, characterized in that the prole of the stirrup section of the trolley matches the cross-sectional profile of the space between the partitions in the leading slat.

References Cited UNITED STATES PATENTS 2,713,899 7/ 1955 Holloway et al 160-199 2,860,697 11/1958 Ensign et al. 160-84 2,863,164 12/ 1958 Schesvold 16-87.4 2,952,312 9/1960 Young et al 160-l99 X 2,959,220 11/1960 Latham 160-199 2,994,371 8/1961 Morseth et a1 160-199 X 3,073,382 1/1963 Zimmerman et al. 160-183 3,167,111 l/1965 Harris 160--183 FOREIGN PATENTS 586,018 12/1958 Italy. 63 8,242 4/ 1962 Italy.

DAVID I. WILLIAMOWSKY, Primary Examiner. HARRISON R. MOSELEY, Examiner.

D. L. TAYLOR, Assistant Examiner. 

1. FOLDING-SLIDING DOOR COMPRISING AN OVERHEAD HORIZONTAL TRACK, A SERIES OF RUNNERS SUPPORTED BY THE TRACK, AND A SERIES OF VERTICALLY EXTENDING SLATS DEPENDING FROM THEIR RESPECTIVE RUNNERS IN A MUTUALLY HINGED ZIG-ZAG ARRANGEMENT, EACH OF SAID SLATS BEING CAPABLE OF PIVOTING ABOUT ITS LONGITUDINAL CENTRAL AXIS WHEREBY THE SERIES OF SLATS CAN BE FOLDED UP AND UNFOLDED LIKE AN ACCORDION, CHARACTERIED IN THAT: (A) EACH OF THE SLATS IN THE SERIES ESSENTIALLY COMPRISING A FLAT HOLLOW PROFILE OF EXTRUDED PLASTICS INCLUDING A PAIR OF PARTITIONS SPACED FROM THE ENDS OF THE PROFILE INTERCONNECTING THE OPPOSITE FACE WALLS OF THE PROFILE AT LOCATIONS ENCLOSING THEREBETWEEN THE LONGITUDINAL CENTRAL AXIS OF THE LATTER; (B) EACH OF THE RUNNERS COMPRISES A STIRRUP SECTION ENCASED IN THE UPPER END OF THE SLAT BETWEEN SAID PARTITIONS, A CYLINDRICAL NECK SECTION PROTRUDING OUTWARDLY FROM THE STIRRUP SECTION IN ALIGNMENT WITH SAID LONGITUDINAL CENTRAL AXIS, AND AN ENLARGED HEAD SECTION ON SAID NECK SECTION COMPRISING A SPHERICAL SURFACE TURNED TOWARDS THE STIRRUP SECTION, SAID STIRRUP 